EGFR and cancer: Blood samples were obtained from cancer patients with defined driver gene hotspot mutations, including EGFR-T790M (n = 32), EGFR-L858R (n = 28), BRAF-V600E (n = 13), PI3KCA-E545K (n = 13), KRAS-G12C (n = 13), and KRAS-G12V (n = 6).